Laser marking has been utilized to produce decorative or simulated patterns or images on work pieces of various materials, including, for example, metals, plastics, wood, and textiles. In some applications, as well known in the field of laser marking, the shade and/or depth of the laser marking may be varied by adjusting one or more of a number of parameters associated with a laser marking apparatus (e.g., a CO2 or YAG laser), including, for example, the power or intensity of the laser source, the rate of movement of the laser beam over the material to be marked, the focus or “spot size” of the laser beam on the surface of the work piece, the duty cycle or pulse rate of the laser beam, and the number of passes of the laser beam over a specific location on the work piece. These types of conventional adjustments during the laser marking operation, used for decades in laser marking various materials, may be used to produce various images and patterns on a work piece.
To produce a laser marked pattern or image having portions of varying shades, an electronically stored image corresponding to the image to be marked may be generated, imported, or otherwise captured. The relative shade of each discrete location on the captured image may be associated with or calibrated to one or more stored power-related parameters of the laser marking apparatus (e.g., laser intensity, rate of movement of the laser beam, duty cycle, or number of passes), such that the laser marking apparatus may be programmed using the stored parameters to reproduce the captured image on the work piece. The laser parameters may be adjusted during operation of the laser marking apparatus in accordance with the stored parameters for each location to be marked.